Vitamin B₁₂and Marine Ecology. IV. The Kinetics of Uptake, Growth and Inhibition inMonochrysis Lutheri

57 Co-labelled vitamin B 12 was used to study the kinetics of vitamin B 12 limitation in Monochrysis lutheri in continuous and exponentially growing batch cultures and in washed cell suspensions. Specific growth rate in the chemostats was found not to depend directly on medium substrate concentration but on the concentration within the cells (cell quota), obeying a hyperbolic equation of the form